一、Project background

transportation development contribute to all industry flourish.The report of the 19th national congress of the communist party of China made a major judgment that "socialism with Chinese characteristics has entered a new era", which is clear that the major strategy of building a transportation power and endow the transportation industry with a new mission in the new era.

From the first Hujia expressway launched today, after 30 years of trial and effort ,domestic highway has experienced from construction stage to operation stage  mainly, constantly facing with the new requirements and new challenges of social and economic development , meanwhile industry management also faces with the objective requirements of transforming from management to service, so the highway operation is confronted with the challenge of safety、efficiency and  unobstructed road.

By the end of 2017, there were 136,500 kilometers of expressways, according to 《statistical bulletin on the development of the transport industry in 2017》 released by the ministry of transport. And by the end of 2017, the number of motor vehicles in China had reached 310 million and will increase to 500 million by 2020, according to the ministry of public security's transportation administration.How to solve the dynamic capacity contradiction between road network capacity and traffic demand under the condition of increasing traffic volume, so how to effectively improve the safety of highway operation and road capacity has become a major problem in highway operation management in our country.

二、Highway operation safety existing outstanding problem  of Highway operation safety

Compared with the middle and low grade highway, the intelligent level of expressway has been higher since the early stage of construction.At the same time, three systems of communication, monitoring and charging have been built。

In a period of time, the construction of video monitoring system greatly improved the level of highway operation monitoring to a certain extent But its disadvantages have been increasingly emerging:

The traditional video detection method has a high false alarm rate:

It cannot work properly In night, glare, rain, snow, fog, smoke, fire and other harsh environmental conditions

There are many cases of false alarm and underreporting. There is a Wolf coming.

The timeliness of abnormal event recognition is poor;

The detection of abnormal events mainly depends on the way of reporting form patrol personnel and traffic police and also complaint telephone, etc. The system lacks active identification and reporting ability of abnormal events, and the timeliness of abnormal events detection is low.

The watcher of the monitoring center can identify the event by the way of watching video manually, which is easy to appear the blind area of logic monitoring.

Highway patrol personnel often goes on patrol according to the scheduled line, so timeliness of potential accident found is poor.

There is a lack of accurate traffic monitoring and control system in expressway.

"Monitoring" should be the monitoring of data, including: climate data, traffic flow data, and traffic event data.

"Control" should be the control of traffic flow, including: main line variable speed limit control, ramp entrance control, channel control.

三、Advanced key technology

Intelligent traffic dynamic monitoring and early warning control technology with precise perception can maximize the consistency of driving environment. Precise basic data includes:

Traffic parameters: traffic volume, traffic density, traffic flow speed, occupancy ratio, congestion degree;

Traffic incidents: slow, congestion, queuing, parking, reversing, accidents, debris ; Breaking in by pedestrians or animals;

Meteorological parameters: temperature, humidity, visibility, wind direction, wind speed, climate conditions, etc.

Road parameters: pavement conditions, linear conditions, etc.

The operation safety and precision monitoring system for expressway (main line) and highway (tunnel) includes omnidirectional wide-area millimeter wave surface monitoring WSDR radar sensor, wind direction indicator, anemometer, visibility sensor, temperature & humidity & pressure sensor, HD camera and C-ITS vehicle-road communication device on the road side.

For the first time, the system applies the accurate sensing technology based on omnidirectional wide-area millimeter-wave radar sensor ("WSDR" radar sensor) to the operational safety dynamic monitoring of expressways (tunnels), which greatly improves the accuracy and real-time identification of security risk events. Sex. Through the accurate road condition sensing and data acquisition of millimeter wave radar, combing with the real-time analysis of the back-end hardware and software system, the system performs to real-time and comprehensive intelligent operation safety monitoring, analysis, event detect, accident warn and security control on the expressway (tunnel). To enable the management personnel to automatically identify the operational safety risks, special events and on-site people, vehicles, road surface debris and other information in the monitoring center. After the system intelligently processes and analyzes the road conditions and events,  according to the risk level by variable information signs for automatic warning and automatic traffic control, so monitoring personnel can quickly carry out emergency response with emergency plans, and finally improve comprehensive prevention and safety management capabilities; At the same time, combining with road warning system, it provides accurate and real-time road comprehensive information for vehicle drivers, which minimizes the occurrence of secondary accidents and secondary accidents at the most extent, and increases the comprehensive social and economic benefits of the road sections while reducing the accident rate and improving road traffic capacity.

(1) Advanced accurate real-time acquisition and processing platform for traffic operation dynamic big data 

The system adopts an advanced big data platform. The front-end sensor uses a frequency-modulated continuous millimeter wave to perform a panoramic scanning perception of 4 Hz per second for the running environment of the road segment. Each scan forms 800,000 latitudes including latitude and longitude, direction angle, distance, speed and frequency. Wave data. A single sensor monitors distances to 1000 meters, working under all weather conditions and full illumination conditions. 24 hours of full-day scanning produces massive data of up to 10TB. High-level FPGA processing units are used to aggregate, layer and classify each echo data, removing clutter, extracting targets, calculating and merging, and finally forming accurate data such as real-time latitude, longitude, speed, size, direction angle, direction angle meter, running track of vehicles, pedestrians, animals, and objects, as well as Real-time traffic analysis data, such as road traffic flow, average speed and lane occupancy. The system also supports massive data storage and calculation. Compared with the traditional video surveillance solution, it not only realizes precise, real-time, full data acquisition and monitoring of traffic dynamics, accurate automatic identification of operational security risks, but also supports internal data sharing and digital backtracking of the event truly,which realizes the monitoring and control of the intelligent and digital security of the road platform operation security risk by the monitoring platform.

(2) All-weather traffic event monitoring, real-time alarm

The traffic event data processing server further analyzes and processes the dynamic data of the road segment, intelligently extracts traffic abnormal event data, and outputs abnormal events, such as over-speed, low speed, slow motion, accident, congestion, parking, retrograde, U line, pedestrian, animal, throwing, etc. The sound and light form generates system alarm, and forms standard xml data format to be sent to the intelligent traffic warning and integrated control server. 

At the same time, the system can still set custom rules according to user requirements, and the system will automatically alarm the traffic behavior beyond the custom parameters. It also supports digital backtracking of events, event track playback and historical data query.

(3) Integrate existing video surveillance systems

The video integration module of the system can be integrated with various video surveillance systems of existing road sections. When the radar detects an abnormal event, it can automatically call the surveillance camera or the PTZ camera closest to the event location to point to the event location according to the location of the event. It is convenient for the monitoring personnel to check and confirm the situation in time, track and verify the abnormal events, and carry out emergency treatment in the shortest time.

(4) Tunnel operation safety risk warning and emergency guidance escape

The system can perform pre-disaster warning on tunnel operation security risks. Before a fire or dangerous goods transport vehicle collision accident, the system can early detect the vehicle's emergency deceleration, faulty parking, over-speed, collision, etc.; when the fire smoke, temperature sensor or environmental monitoring sensor does not reach the starting conditions, the system will track the target and automatically call the camera for monitoring personnel to track and review, and take emergency measures in a timely manner. Through the intelligent tunnel operation safety risk monitoring, it can realize automatic identification and early warning of risks, such as fire, hazardous chemicals leakage and secondary derivative accidents.

After the system is integrated with the existing fire protection system data, the radar monitoring function can penetrate visual invisible obstacles such as smoke, deflagration, water spray, accurately locate the real-time running state of the trapped vehicle and the escaped person, automatically establish a quick guiding strategy, open the escape route quickly guides the escape personnel to the nearest escape route through sound and light, and provide the earliest time window for event handling and rescuing, which maximize lifesaving and reducing the hazard of accidents.

(5) Real-time intelligent risk warning and intelligent integrated                   automatic control

The traffic operation safety risk warning and control strategy processing module combing the road segment monitoring data and other sensor data according to traffic density, speed, traffic, and various risk events, including upstream main line flow, ramp flow, road climate data, environmental data, and fire protection. System data, etc., carry outs big data comprehensive analysis and judgment, builds an algorithm model, and automatically formulate an optimal control strategy, to provide early warning release and comprehensive automatic control through intelligent early warning release and integrated automatic control system. It provides the real-time warning for manager, the warning, while guidance information and control commands are automatically released to the variable information signs and variable speed limit signs of the tunnel entrance, the upstream road section and the ramp section, which effectively regulated and induct he traffic flow rate and traffic flow.

Through a series of optimized warning information and control instructions, the average speed, traffic volume and other control objectives of the main line traffic flow are automatically adjusted. While reducing the pressure on monitoring and management personnel, it can greatly improve the capabilities of intelligent automatic identification, early warning and prevention and control  safety risks, reduce safety hazards and decrease the accidents incidence, mitigate the consequences of accidents, and serious traffic accidents, guarantee safe production and transportation , and greatly improve road capacity and traffic efficiency , and it helps realize automatic identification, automatic warning and automatic control of intelligent safety risk management of main line operation, which lays a solid foundation for building a safe, efficient and green wisdom of modern transportation system.

(6) Data storage and digital backtracking

The system can automatically record real-time related data, business alarm information, business logs and historical events real-time trajectories of each abnormal event in the past three months. And it also can realize the free call view of each management level sub-rights.

It can provide historical data query of tunnel traffic flow, and generate daily, monthly and annual reports of traffic flow with the functions of historical queries for traffic anomaly alarms, report generation and printing.

(7) System expansion and future applications

In the future, the system can realize information interaction among autonomous vehicle, vehicle terminal and the driver's hand-held terminal, and realize the coordinated intelligent transportation. 
The current auto-driving field has reached a consensus on “the car is becoming smarter and the infrastructure must be transformed”. At this stage, autonomous vehicles need to rely on expensive lidar sensors. If each vehicle is equipped with a laser radar, the cost per vehicle will be increased to several hundred thousand yuan; but if similar equipment is assembled on the road side, vehicles can share road condition data, and the cost will be greatly reduced.

The system is installed on the road side, which can share real-time and accurate traffic flow data with the vehicle. Before achieving complete automatic driving, a safe, stable and reliable automatic flow queuing system can be realized.